package model;


import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

public class UserDao {
    //根据用户ID查询用户信息
    public User getUserById(int userId) {
        Connection connection = null;
        PreparedStatement statement = null;
        ResultSet resultSet = null;

        try {
            connection = DBUtil.getConnection();
            String sql = "select * from user where userId = ?";
            statement = connection.prepareStatement(sql);
            statement.setInt(1,userId);
            resultSet = statement.executeQuery();

            if (resultSet.next()) {
                User user = new User();
                user.setUserId(resultSet.getInt("userId"));
                user.setUsername(resultSet.getString("username"));
                user.setPassword(resultSet.getString("password"));
                return user;
            }

        } catch (SQLException e) {
            throw new RuntimeException(e);
        } finally {
            DBUtil.close(resultSet,statement,connection);
        }
        return null;
    }

    //根据用户名查询用户信息
    public User getUserByName(String username) {
        Connection connection = null;
        PreparedStatement statement = null;
        ResultSet resultSet = null;

        try {
            connection = DBUtil.getConnection();
            String sql = "select * from user where username = ?";
            statement = connection.prepareStatement(sql);
            statement.setString(1,username);
            resultSet = statement.executeQuery();

            if (resultSet.next()) {
                User user = new User();
                user.setUserId(resultSet.getInt("userId"));
                user.setUsername(resultSet.getString("username"));
                user.setPassword(resultSet.getString("password"));
                return user;
            }

        } catch (SQLException e) {
            throw new RuntimeException(e);
        } finally {
            DBUtil.close(resultSet,statement,connection);
        }
        return null;
    }

    //添加用户
    public void registerUser(String username,String password) {
        Connection connection = null;
        PreparedStatement statement = null;

        try {
            connection = DBUtil.getConnection();
            String sql = "insert into user values (null,?,?)";
            statement = connection.prepareStatement(sql);
            statement.setString(1,username);
            statement.setString(2,password);
            statement.executeUpdate();


        } catch (SQLException e) {
            throw new RuntimeException(e);
        } finally {
            DBUtil.close(statement,connection);
        }
    }
}
